test: Add and update some init command tests, linting and code comment changes

[SarahFrench]

This PR:

• Adds an explicit test for use of -backend=false - TestInit_backend_initFromState. Previously this was only tested indirectly when testing the get providers feature.
  • This meant also renaming the test TestInit_backend to TestInit_backend_initFromConfig
• Updates TestInit_multipleArgs to be a bit more explicit, and add context about what the test is for
• Addressing inaccurate // Create a temporary working directory that is empty code comments that have proliferated by copy and paste
• Linting stuff

Target Release

N/A

Rollback Plan

• If a change needs to be reverted, we will roll out an update to the code within 7 days.

Changes to Security Controls

Are there any changes to security controls (access controls, encryption, logging) in this pull request? If so, explain.

CHANGELOG entry

• This change is user-facing and I added a changelog entry.
• This change is not user-facing.

[github-actions]

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